The invention relates to semiconductor process monitoring, and more specifically relates to an apparatus and method for determining wear indication in semiconductor manufacturing processes such ion beam etching systems and ion beam deposition systems.
The manufacture of semiconductors often includes steps that occur in an environment which causes rapid wear to the involved tooling. Examples of such systems include both deposition/implantation systems and material removal systems. The preferred embodiment of the invention that is disclosed herein is directed to a non-selective material removal system, but one skilled in the art would easily recognize that the invention could be utilized in any semiconductor manufacturing system that causes wear to the tooling in the system due to the harsh environment in certain steps of the semiconductor manufacturing system.
The tooling in the semiconductor environment includes latches and springs that are used to hold product in place so that certain materials, usually metals, can be deposited on or etched away from the product. Wear to the latches and springs causes inefficient latching that leads to an increased number of damaged products.
There are a number of non-selective material removal systems used in the processing of electrical parts such as semiconductors. The ion beam etch process is an example of one such system. The ion beam etch system removes/etches metal in a vacuum plasma environment. In non-selective material removal systems, the manufactured product is etched to provide a specific design feature using an ion beam. However, the non-selective nature of the system results in degradation to elements of the tooling of the system such as the latches on the tool stage, springs or shields. Eventually, the degradation reaches a point where the elements of the tool system need to be replaced. It has heretofore been difficult to determine the ideal or optimum replacement interval for the various elements of the system.
There are various known methods to monitor the wear in semiconductor manufacturing systems. One such method is described in U.S. Patent Application Number 2003-0022397 to Hess et al. which discloses a device that provides for a monitoring system of a through-substrate etching process by providing a sacrificial electrode in proximity to a desired etch window on the substrate. The electrical properties of the sacrificial electrode provide for the endpoint detection of wear to the substrate.
Another known method to monitor wear in semiconductor manufacturing systems is described in U.S. Pat. No. 6,394,023 to Crocker. Crocker teaches the cleaning of parts that require cleaning due to a buildup or deposition of material by utilizing a visual indicator formed in a surface that is to be subjected to a cleaning process. The visual indicator is designed into the substrate or device.
Yet another method used to monitor wear in semiconductor manufacturing systems is described in U.S. Pat. No. 5,947,053 to Burnham, et al which discloses a wear through indicator that is specific to multi-layer devices. The multi-layer device has a detecting layer designed and built into the device.
There remains a need for a wear indicator for semiconductor manufacturing systems having harsh environments where the indicator is simple, real-time, point of use and can be retrofitted to existing systems. There also remains a need for a wear indicator for semiconductor manufacturing systems that can simply and in real-time determine the ideal or optimum replacement interval for the various elements of the system. A device and/or method to meet these needs will result in lower manufacturing costs by optimizing maintenance schedules and reducing production/tooling down time.